The present invention generally relates to wireless communication networks, and particularly relates to determining radio interference characteristics within a wireless communication network.
Costs and other practical considerations, such as the ability to acquire suitable tower locations, drive wireless network configurations toward an optimum siting solution where a minimum arrangement of cellular base stations within the network coverage area provides the needed radio coverage characteristics. Wireless network planning focuses on determining the best sites for the radio base stations within the coverage area.
Software planning tools use radio propagation models in combination with terrain data associated with the planned coverage area to provide estimates of radio signal propagation characteristics. However, because of the significant complexity involved in real-world radio signal propagation, computer modeling seldom provides a complete picture of radio signal propagation within the network area. Network planners adopt various other approaches to garner more accurate and complete information about radio signal propagation and attendant interference conditions within the coverage area.
Several non-simulation approaches allow wireless service providers to develop detailed, accurate information about actual radio signal propagation, and the actual nature and extent of radio interference within the network coverage area. One technique uses dedicated roving mobile stations that move through various coverage areas of the wireless network to collect signal data. While this approach does allow accurate characterization of signal propagation and interference within the network, it is time consuming and expensive. Other techniques involve the use of network receivers, namely, radio base station receivers, installed at fixed locations throughout the network coverage area. Generally, these fixed receivers are used to collect data from random mobile stations operating within one or more of the coverage areas associated with the network receivers.
With this latter approach, a wireless service provider can use existing base stations to develop a detailed picture of signal propagation and interference, particularly inter-cell interference, within the wireless coverage area. Such information aids in the expansion and modification of the existing wireless network, and may be of great use in terms of implementing new, overlaid wireless services within the same coverage area. An example of this approach would be where a given wireless service provider begins overlaying advanced wireless services, such as third generation (3G) services onto an existing second generation (2G) wireless network.
One difficulty with the use of network base stations is that each base station is configured to receive and process access burst types appropriate for its coverage area. Generally, a given base station is configured to either process normal access bursts or abbreviated access bursts depending on cell size. Thus, during interference measurement modes, the base station may be expected to measure signals originating from mobile stations operating in surrounding cells that impose a different access burst requirement on mobile stations that is used by the base station performing the measurement.